back-staff and case

Invented by Capt. John Davis Around 1594, the back staff was a more accurate and easier instrument to use then the cross-staff. The back staff was used for nearly 200 yrs.

To use;The larger arch has a sight vain, that you sight the horizon from the vain through a slot in the horizon block located at the opposite end of the staff. With the sun behind you, you then adjust the shadow vain on the smaller arch until it casts a shadow onto the horizon vain precisely where the horizon has been sighted. You then add the degrees from both arch’s and use the total degrees to calculate the angle of the object off the horizon, and that number to calculate your latitude.

The Case;One of the museum back-staffs I found was in an original case. From the photograph I was able to reproduce the case, excluding the hinges and clasps.

These are both just wonderful pieces. Your time and effort in researching them was definitely worth it.A couple of questions.How big are they (cross staff as well)?Are they for your personal nautical collection or will they be on display in a maritime museum somewhere?Personally I think they would be great mantle art in any sailor’s home.

Thanks you guys for your comments, really makes me feel awesome coming from such talented people like yourselves. Dean, totally jealous of your new router station! I’d never come out of my shop if I had such a station!

Hi, sorry for my absence in replying to all your fantastic comments. These pieces will be in my personal collections of navigational tools and history. When I check out of this world, they will be donated to a reputable maritime museum.

I’ll try to find a few sketch depicting how each instrument is used. will post as soon as I find them.